1. Field of the Invention
The present invention relates to thermal transfer material, and a printing method and printer used with the same. More particularly, the present invention relates to thermal transfer material suitable for printing to an image receiving material of which a printing surface is not very smooth, and a printing method and printer used with the same.
2. Description Related to the Prior Art
Material with a not smooth surface, such as paper or fabric, has a characteristic that it is difficult for the surface to receive ink stably. It happens that dots are missing or out of order. Images are very hard to be recorded with high quality. There is a known system in which the image is created once on an intermediate material, and then is transferred to an image receiving material. JP-A 05-000575 discloses transfer material, which includes a support with releasability, and a layer of developer agent overlaid on the support.
In the printer according to this prior document, photosensitive pressure-sensitive material of a continuous sheet, while fed, is exposed by light reflected by an original. In the photosensitive pressure-sensitive material, a photosensitive pressure-sensitive layer includes a great number of micro capsules distributed uniformly. Each of the micro capsules contains dye precursor, photo-setting resin and photo polymerization initiator. The photo-setting resin is hardened in response to application of exposure light. A certain number of micro capsules in the photosensitive pressure-sensitive material are hardened, the certain number being proportional to an amount of the exposure light. Then the photosensitive pressure-sensitive material is placed on the transfer material, and passed together between press rollers. Then the remainder of the micro capsules without being hardened even after the exposure are destroyed. The dye precursor flows from the micro capsules, and reacts upon the developer agent in a developer layer, so that a full-color image is created in the developer layer of the transfer material.
The image of the original is read by a scanner. A computer is operated to detect a colored portion in the image. Then a thermal printer is used to produce a printing plate of a screen sheet according to the colored portion of the image as detected by the computer, the screen sheet consisting of mesh sheet of nylon or the like and thermosensitive resin overlaid on the mesh sheet. To be precise, the thermosensitive resin is melted in positions corresponding to the colored portion of the image of the original. Only portions of the mesh sheet remain those positions.
After this, the screen sheet is placed on the transfer material by positioning the image in the transfer material suitably. Then polyolefin resin dispersion liquid is pressed and applied as a thermoplastic resin coating to the transfer material. When the screen sheet is separated and dried. The thermoplastic resin is kept with the transfer material to cover the image.
The thermoplastic resin of the transfer material is placed on an image receiving sheet material of polyethylene terephthalate film, and is passed together between hot press rollers, to be attached thereto. Then the transfer material is fused to the image receiving material by means of the thermoplastic resin. After cooling down to the room temperature, the support in the transfer material is peeled. The portion of the transfer material with the image is transferred to the image receiving material.
The above-mentioned printer only forms the image in the developer layer of the transfer material. For transferring the developer layer to the image receiving material with the image, the additional steps are required, the steps including the step of providing the image of the transfer material with the thermoplastic resin, the step of fusing the transfer material to the image receiving material by means of the thermoplastic resin, and the step of peeling the support of the transfer material. Thus, the printer has a shortcoming in the complexity in the printing process and necessity of much time for printing.